Anti-inflammatory and anti-oxidant action of tadalafil in testicular regeneration process after heat stress.

Tadalafil, a potent phosphodiesterase inhibitor 5 (PDE-5), is commonly used for the management of erectile dysfunction. However, its therapeutic potential extends beyond this indication. This study aimed to investigate the impact of tadalafil on the recovery of testicular parenchyma in male Wistar rats exposed to testicular thermal stress. Fifty-four Wistar rats were subjected to testicular thermal stress and randomly assigned to receive either tadalafil treatment (TAD) or no treatment (control). TAD was administered intraperitoneally at a dose of either 0.9 mg/kg or 1.8 mg/kg. Biometric parameters, histopathological assessment of the testis, serum testosterone levels, oxidative stress, and interleukin levels were evaluated on days 7, 15, and 30 after thermal shock. The animals were euthanized at the end of each experimental period, and samples were collected. TAD treatment maintained testicular weight and reduced the testicular degenerative process up to day 7 post-injury. However, despite TAD therapy, serum testosterone levels were decreased in the treated groups at days 7 and 15 post-thermal stress. TAD also decreased TNF-α and NO levels at different doses but had no effect on IL-6. The treatment with TAD after heat shock demonstrated anti-inflammatory and antioxidant properties but did not prevent the aggravation of testicular lesions in subsequent periods, even with the systematic reduction in TNF-α and NO levels. Therefore, this selective PDE-5 inhibitor, at the dosages used, did not have a positive impact on testosterone levels during the post-thermal stress period, which could compromise the resumption of the spermatogenic process.

Effect of dosage of orally administered 17α-methyltestosterone on sex reversion of the yellowtail tetra Astyanax lacustris (Lütken, 1875).

The females of yellowtail tetra (Astyanax lacustris), known as the freshwater sardine, are approximately 1.33 times larger than males, and thus, all-female monosex culture would increase production and reduce size variability. The present work aimed to identify the optimal dose of 17α-methyltestosterone (MT) to be used in the masculinization of A. lacustris for indirect sex reversal. Three different concentrations of MT (20, 40, and 60 mg/kg of feed in the diet) were fed to the fry for 30 days. Thirty adult individuals from each treatment, including the control (0 mg MT/kg), were evaluated for gonadal development, morphological and histological sexual identification, zootechnical performance, and the possible genotoxic effect caused by prolonged exposure to MT. MT significantly (P<0.01) affected the differentiation of the gonads, with the presence of possible inhibitory effects in all treatments. Intersex individuals were present in the 20 and 60 mg MT/kg treatments. All treatments were able to masculinize A. lacustris and the treatment with the lowest hormone concentration produced the highest percentage of males 76.7%, while the control had 46.7% males. The presence of erythrocyte nuclear alterations indicated a possible cytotoxic effect of MT in treatments 40 and 60 mg MT/kg, however, the use of the hormone did not affect the growth and the survival of the individuals. Thus, the use of MT is a viable option for obtaining neomales as a first step into the production of all-female progenies.

Histomorphometric changes of the fore-stomach of lambs fed with diets containing spineless cactus genotypes resistant to Dactylopius sp.

The histomorphometric parameters of the fore-stomach epithelium of lambs fed with spineless cactus genotypes resistant to Dactylopius sp. were evaluated. Thirty-two lambs (23.0 ± 2.06 kg body weight) were distributed in a completely randomized design with four treatments and eight replications. The treatments consisted of the base diet and diets in which part of the elephant grass hay and all ground corn was replaced by the Miúda, IPA-Sertânia, or Orelha de Elefante Mexicana (OEM) spineless cacti. The keratin layers of the ruminal epithelium of the animals consuming the spineless cacti Miúda and OEM presented greater thickening relative to the control diet: 47.31, 41.30, and 25.81 µm, respectively. The heights of the ruminal papillae were higher in the animals that were fed with the OEM spineless cactus. The Miúda spineless cactus caused an enlargement in the keratinized layer of the reticulum epithelium, as well as a decrease in the thickness of the non-keratinized layers. The diet containing OEM spineless cactus resulted in greater thickening of the keratin layer of the omasal epithelium and decreased thickness of the non-keratinized layers. The spineless cacti Miúda and OEM changed the morphology of the fore-stomach epithelium and increased the dry matter intake and weight gain of lambs.

The Fatty Acid Composition of Vegetable Oils and Their Potential Use in Wound Care.

OBJECTIVE: To evaluate the similarities among fatty acid compositions of vegetable oils sold in the Brazilian market and those present in a reference health product used to treat wounds. METHODS: The relative amounts of fatty acids in 21 types of vegetable oils, purchased in the Brazilian market, were assessed using gas chromatography-mass spectrometry and flame ionization detection. MAIN RESULTS: The studied oils had similar fatty acid compositions to the reference product (caprylic acid, 18.8%; capric acid, 17.4%; oleic acid, 27.5%; and linoleic acid, 28.1%). The presence of caprylic acid (10.45% ± 0.07%), capric acid (5.8% ± 0.75%), lauric acid (45.63% ± 0.93%), and myristic acid (16.33% ± 2.23%) were detected in all the vegetable oils tested. Oleic acid (52.94% ± 12.54%) was present in andiroba, avocado, canola, copaiba, olive, palm, pequi, and pracaxi oils and featured prominently in olive oil (75.8%). Linoleic acid (57.09% ± 8.47%) was present in corn, cottonseed, grapeseed, passion fruit, and sunflower oils and in mixed oils (olive with soybean and sunflower with corn and canola). CONCLUSIONS: Most of the vegetable oils tested are products of plants from tropical climates, where they are abundant and easy to cultivate. It is possible that a balanced composition of fatty acids obtained from natural sources could be an effective alternative treatment for wounds.

Can fractal methods applied to video tracking detect the effects of deltamethrin pesticide or mercury on the locomotion behavior of shrimps?

Shrimps can accumulate environmental toxicants and suffer behavioral changes. However, methods to quantitatively detect changes in the behavior of these shrimps are still needed. The present study aims to verify whether mathematical and fractal methods applied to video tracking can adequately describe changes in the locomotion behavior of shrimps exposed to low concentrations of toxic chemicals, such as 0.15µgL-1 deltamethrin pesticide or 10µgL-1 mercuric chloride. Results showed no change after 1min, 4, 24, and 48h of treatment. However, after 72 and 96h of treatment, both the linear methods describing the track length, mean speed, mean distance from the current to the previous track point, as well as the non-linear methods of fractal dimension (box counting or information entropy) and multifractal analysis were able to detect changes in the locomotion behavior of shrimps exposed to deltamethrin. Analysis of angular parameters of the track points vectors and lacunarity were not sensitive to those changes. None of the methods showed adverse effects to mercury exposure. These mathematical and fractal methods applicable to software represent low cost useful tools in the toxicological analyses of shrimps for quality of food, water and biomonitoring of ecosystems.

Characterization of isoforms of the lectin isolated from the red algae Bryothamnion seaforthii and its pro-healing effect.

Lectins are a structurally heterogeneous group of proteins that have specific binding sites for carbohydrates and glycoconjugates. Because of their biotechnological potential, lectins are widely used in biomedical research. The present study aimed to evaluate the healing potential of the lectin isolated from the marine red alga Bryothamnion seaforthii (BSL). The lectin was purified using ion exchange chromatography with DEAE cellulose and characterized using tandem mass spectrometry. For healing tests, skin wounds were induced in the dorsal thoracic region of mice. These animals were randomly divided into three groups and subjected to topical treatment for 12 days with BSL, bovine serum albumin and 150 mM NaCl. To evaluate the potential of each treatment, the animals were anesthetized and sacrificed on days 2, 7 and 12, respectively. The parameters evaluated included the wound area, the proportion of wound closure and the histological diagnosis. The wound closure was more effective with BSL (Postoperative Day 7 and 12) than controls. The luminal epithelium was completely restructured; the presence of collagen in the dermis and the strongly active presence of young skin annexes demonstrate the potential of treatment with BSL compared with controls. Our findings suggest that BSL has pro-healing properties and can be a potential medical process in the treatment of acute wounds.

Evaluation of testicular degeneration induced by low-frequency electromagnetic fields.

The population exposure to electromagnetic fields (EMF) has been growing in recent decades. The generation, distribution and use of electric energy can generate low-frequency electromagnetic fields. The present study investigates the effects of EMF (60 Hz and 1 mT) on spermatogenesis of rats during different periods of maturation. Wistar rats were exposed to EMF from day 13 of gestation to postnatal day 21 or 90 in three daily applications of 30 min. Plasma testosterone concentration was not changed by EMF exposure; however, histopathological and histomorphometrical analyses of the testes showed testicular degeneration in a subset of animals exposed to EMF. The magnitude of the degenerative process varied between those individuals affected, indicating different individual sensitivity to EMF. The main alterations observed through transmission electron microscopy were highly electron-dense mitochondria with loss of their organization and cristae. Exposure to 60 Hz and 1 mT EMF can disturb spermatogenesis and may produce subfertility or infertility.

Clinical and histopathologic study of the use of gangliosides for nerve regeneration in rats after axonotmesis.

PURPOSE: This study involved a clinical and histopathologic evaluation of the use of gangliosides in nerve regeneration, using an experimental model with higher vertebrates. MATERIALS AND METHODS: Forty Sprague Dawley rats had their right sciatic nerve crushed for 1 minute in a hemostatic tweezer. The animals were divided into experimental and control groups. The animals in the experimental group received an intramuscular injection of gangliosides in the left thigh for 25 days, whereas those in the control group received infiltrations of distilled water. A clinical evaluation of gait was made 24 hours and then 45 days after the surgical intervention, and a histopathologic evaluation of the sciatic nerves was performed after 45 days. RESULTS: There were no signs that the use of gangliosides significantly altered the animals' gait after 45 days. The animals in the experimental group had a greater frequency and intensity of inflammatory response than seen in the control group. CONCLUSION: The systemic use of gangliosides produced no improvement in gait and led to a more frequent and intense inflammatory response at the site of injury.

Neonatal treatment with naloxone increases the population of Sertoli cells and sperm production in adult rats.

Endogenous opioid peptides play an important role in the ontogenesis of the functional and morphological parameters of the seminiferous epithelium. The aim of this study was to evaluate the effects of neonatal manipulations with naloxone, an opioid antagonist, on the population of Sertoli cells and on sperm production in adult rats. Rats were assigned to receive 8 mug per gram of body weight twice a day with interval of 8 h of naloxone and they were compared to a control group receiving saline. Naloxone groups presented the following findings when compared to the control group: increased body weight from the 2nd to the 27th day; a smaller seminiferous epithelium height, smaller seminiferous tubule diameter, increased number of Sertoli cells and daily sperm production per testis, increased daily sperm production per gram per testis and increased total length of the seminiferous tubule of the treated groups. According to our study, the neonatal treatment with naloxone during the critical period of testis development was able to change the proliferative dynamics of Sertoli cells by an intra and/or extra testicular blockage of opioid receptors, confirming the direct relation between the number of Sertoli cells and the number of spermatozoids.